shithub: aubio

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python/lib/aubio/midiconv.py: clean up, add some documentation

--- a/python/lib/aubio/midiconv.py

+++ b/python/lib/aubio/midiconv.py

@@ -1,23 +1,26 @@

 # -*- coding: utf-8 -*-

+""" utilities to convert midi note number to and from note names """

 import sys

-PY3 = sys.version_info[0] == 3

-if PY3:

-    string_types = [str]

+py3 = sys.version_info[0] == 3

+if py3:

+    str_instances = [str]

+    int_instances = [int]

 else:

-    string_types = [str, unicode]

+    str_instances = [str, unicode]

+    int_instances = [int, long]

 def note2midi(note):

     " convert note name to midi note number, e.g. [C-1, G9] -> [0, 127] "

     _valid_notenames = {'C': 0, 'D': 2, 'E': 4, 'F': 5, 'G': 7, 'A': 9, 'B': 11}

-    _valid_modifiers = {None: 0, u'♮': 0, '#': +1, u'♯': +1, u'\udd2a': +2, 'b': -1, u'♭': -1, u'\ufffd': -2}

+    _valid_modifiers = {None: 0, u'♮': 0, '#': +1, u'♯': +1, u'\udd2a': +2,

+                        'b': -1, u'♭': -1, u'\ufffd': -2}

     _valid_octaves = range(-1, 10)

-    if type(note) not in string_types:

-        raise TypeError("a string is required, got %s (%s)" % (note, str(type(note)) ))

-    if not (1 < len(note) < 5):

-        raise ValueError(

-                "string of 2 to 4 characters expected, got %d (%s)" %

-                (len(note), note))

+    if isinstance(note, str_instances):

+        raise TypeError("a string is required, got %s (%s)" % (note, str(type(note))))

+    if len(note) not in range(2, 5):

+        raise ValueError("string of 2 to 4 characters expected, got %d (%s)" \

+                         % (len(note), note))

     notename, modifier, octave = [None]*3

     if len(note) == 4:

@@ -48,15 +51,14 @@

 def midi2note(midi):

     " convert midi note number to note name, e.g. [0, 127] -> [C-1, G9] "

-    if type(midi) != int:

+    if isinstance(midi, int_instances):

         raise TypeError("an integer is required, got %s" % midi)

-    if not (-1 < midi < 128):

-        raise ValueError(

-                "an integer between 0 and 127 is excepted, got %d" % midi)

-    midi = int(midi)

+    if midi not in range(0, 128):

+        raise ValueError("an integer between 0 and 127 is excepted, got %d" % midi)

     _valid_notenames = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B']

-    return _valid_notenames[midi % 12] + str( int(midi / 12) - 1 )

+    return _valid_notenames[midi % 12] + str(int(midi / 12) - 1)

 def freq2note(freq):

+    " convert frequency in Hz to nearest note name, e.g. [0, 22050.] -> [C-1, G9] "

     from aubio import freqtomidi

     return midi2note(int(freqtomidi(freq)))